Question

若1+2+3+...+n=55,求代数式(x^ny)(x^n-1y^2)(x^n-2y^3)...(x^2y^n-1)(

Answer 1

x^n * x^(n-1) * .* x=x^(n + n-1 + n-2 +.+1)=x^55.

y * y^2 * .* y^n=y^(1 + 2 + 3 +.+n)=y^55.

所以答案为：x^55 * y^55.